Pain in the genitourinary tract is usually associated with distention of a hollow viscus (ureteral obstruction, urinary retention) or the capsule of an organ (acute prostatitis, acute pyelonephritis). Pain may be local or referred. Pain associated with malignancy is usually a late manifestation and indicative of advanced disease.
Pain of renal origin is usually located in the ipsilateral costovertebral angle. It may radiate to the umbilicus and may be referred to the ipsilateral testicle in men or the labium in women. With infection, the pain is typically constant, whereas with obstruction it may come and go. Nausea and vomiting may result from reflex stimulation of the celiac ganglion. Patients with intraperitoneal pathology will typically lie motionless to avoid pain, while patients with kidney disease will move about to try to find a more comfortable position.
Ureteral pain is typically acute and a result of obstruction. Distention of the ureter along with hyperperistalsis and spasm of the smooth muscle of the ureter may result in two different pain patterns. Distention may cause a constant dull ache, while the spasms result in colic. The site of obstruction is often predicted by the site of pain. Upper ureteral obstruction may result in pain referred to the scrotum in males or to the labium in females. Midureteral obstruction may cause pain in the lower quadrant and thus may be confused with appendicitis in right-sided ureteral obstruction or diverticulitis in left-sided ureteral obstruction. Lower ureteral obstruction may cause inflammation of the ureteral orifice and thus be associated with symptoms of vesical irritability.
Acute urinary retention results in severe suprapubic discomfort. Chronic urinary retention is usually painless despite tremendous vesical distention. Suprapubic pain not related to the act of micturition is rarely vesical in origin. Acute cystitis pain is usually referred to the distal urethra and is associated with micturition.
Prostatic pain is associated with inflammation and is located in the perineum. Pain radiates to the lumbosacral spine, inguinal canals, or lower extremities. Because of its location near the bladder neck, inflammatory processes of the prostate result in irritative voiding complaints.
Pain in the flaccid penis is secondary to inflammatory processes caused by sexually transmitted diseases or paraphimosis, a condition of the uncircumcised male in which the retracted foreskin is trapped behind the glans penis, resulting in vascular congestion and painful swelling of the glans. Pain in the erect penis may be due to Peyronie disease (fibrous plaque of the tunica albuginea, resulting in painful curvature of the erect penis) or to priapism (prolonged erection).